JP2002031249A - Valve element structure for metal seat butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide valve element structure for a metal seat butterfly valve in which a valve element is opened/closed between a totally open position and a totally closed position by reverse operation of 90 deg. and becomes parallel with the axis of a passage in the totally open attitude. SOLUTION: The butterfly valve is constituted by providing the valve element 22 in a valve casing 12 rotatably around the axis of a valve stem 18, providing a valve element seat 24 formed of a metallic material, at the peripheral edge part of the valve element 22, and forming a valve element seat face 24a coming in watertight sliding contact with a valve easing seat 13, at the outer peripheral surface of the valve element seat 24. The valve element seat 24 is so shaped that a plane B including the centerline of the valve element seat face 24a inclines at a specified angle α to a valve casing passage cross section A in the totally closed state where the valve element 22 is arranged parallel with the valve casing passage cross section A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve body structure of a metal seat butterfly valve, and more particularly, to a valve body in which the flow in a valve box when fully opened is equalized on both sides of the valve shaft at the boundary. It concerns technology.

[0002]

2. Description of the Related Art For example, in a metal sheet butterfly valve as shown in FIG.
Is provided rotatably around the axis of the valve rod 3, and a valve body sheet 4 made of a metal material is provided around the valve body 2. 1 and held inside by a sealing material 6.

[0003]

As shown in FIG. 6, in the metal seat butterfly valve, the valve body sheet 4 and the valve box sheet 5 are made of a metal material and do not elastically deform. From the heart a to the seat surface 4 of the valve seat 4
When the distances L1 and L2 to the corners 4b and 4c on both sides of a are equal, one corner 4c and the valve box sheet 5 interfere with each other, and the seat surface 4a is brought into contact with the seat surface 5a of the valve box sheet 5. It does not come into contact (shown by the two-dot chain line). For this purpose, as shown in FIG.
A clearance angle is formed in the seat surface 4a so that the seat surface 4a is fully closed in a posture inclined at a predetermined angle α with respect to a normal line n of the seat surface 5a.

As shown in FIG. 8, the processing of the seat surface 4a of the valve seat 4 is performed in the following procedure. That is, the valve body sheet 4 is attached concentrically to the peripheral portion of the valve body 2 by welding or the like, and the valve body 2 is held in a state of being inclined at the predetermined angle α, and the virtual cylindrical processing surface equal to the inner diameter of the valve box sheet 5 The valve body sheet 4 is ground along a two-dot chain line to form a seat surface 4a.

As shown in FIG. 5, the valve body 2 formed by this processing does not become perpendicular to the flow path axis of the valve box 1 in the fully closed position. The valve body 2 is not parallel to the flow path axis of the valve box 1
Are not symmetrical with respect to the flow path axis, so that the flow of fluid in the internal flow path of the valve box 1 becomes unbalanced on the left and right sides of the flow path.

On the other hand, when the valve body 2 is not opened and closed between the fully open position and the fully closed position by the reversing operation of 90 °,
There was a problem that it was difficult to position the valve body 2 in a fully open position parallel to the flow path axis.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and opens and closes a valve body between a fully open position and a fully closed position by a 90 ° inversion operation, and when the valve body is in a fully open position, the valve body is parallel to the flow path axis. It is an object of the present invention to provide a valve body structure of a metal seat butterfly valve.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, a valve structure of a metal seat butterfly valve according to the present invention comprises:
A valve body is installed inside the valve box so as to be rotatable around the axis of the valve stem,
In a butterfly valve in which a valve body sheet made of a metal material is provided on a peripheral portion of the valve body, and a valve body sheet surface that is slidably contacted with the valve box sheet on the outer peripheral surface of the valve body sheet, the valve body sheet includes:
In a fully closed state in which the valve element is disposed in parallel with the cross section of the valve box flow path, the plane including the center line of the valve element sheet surface has a shape inclined at a predetermined angle with respect to the cross section of the valve box flow path.

With the above construction, the valve body is in a posture perpendicular to the flow path axis of the valve box in the fully closed state, and is in a posture parallel to the flow path axis of the valve box in the fully opened state after the 90 ° inversion operation. Since the valve body is symmetrical with respect to the flow path axis, the flow of the fluid in the valve box flow path is balanced on the left and right sides of the flow path.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A metal sheet butterfly valve according to an embodiment of the present invention will be described below with reference to the drawings. 1 to 4, a metal seat butterfly valve 1 is shown.
1 has a valve box sheet 13 arranged inside a valve box 12,
The valve box sheet 13 is made of a cylindrical thin metal material.
The two channels are provided concentrically with the channel center and with a predetermined gap S therebetween.

A pair of valve boxes O is provided between the inner surface of the valve box 11 and the outer peripheral surface of the valve box sheet 13 as a sealing material made of an elastic material.
The ring 14 is arranged at the upstream and downstream positions of the valve box sheet 13, and the valve box O-ring 14 is mounted in an annular groove 15 formed on the inner surface of the valve box 12. Valve box sheet 13
Stopper 1 adjacent to the upstream and downstream ends of the
The stopper 16 locks the valve box sheet 13 in the axial direction of the flow path, and is fixed to the valve box 12 by bolts 17.

The valve stem 18 includes a valve box 12 and a valve box sheet 13.
Is penetrated in a direction perpendicular to the axial direction of the flow path, and is rotatably held by a bush 20 inserted into the boss 19 of the valve box 12. A plurality of Os on the inner and outer peripheral surfaces of the bush 20.
A ring 21 is arranged to seal between the valve stem 18 and the boss 19.

The valve body 22 includes the valve stem 1 inside the valve box sheet 13.
8 is rotatably arranged around the axis, and the pin 23 is
It is connected to. The valve body 22 is provided with a valve body sheet 24 at a peripheral portion. The valve body sheet 24 is made of a metal material, and the valve box sheet 1 is formed on a valve body sheet surface 24a formed on an outer peripheral surface thereof.
3 is in sliding contact with the valve box seat surface 13a in a watertight manner.

As shown in FIG. 4, when the valve body sheet 24 is in a fully closed state in which the valve body 22 is arranged in parallel with the cross section A of the valve box flow path, the plane B including the center line of the valve body sheet surface 24a is a valve. It has a shape that is inclined at a predetermined angle α with respect to the section flow path A of the box. The processing of the valve body sheet surface 24a of the valve body sheet 24 is performed in the following procedure. As shown in FIG. 3, it is assumed that a plane D is inclined at a predetermined angle α with respect to a plane C passing through the axis of the valve body 24 (coincident with the axis of the valve stem 18). A valve body sheet 24 is attached to the peripheral edge of the valve body 22 by welding or the like, and the valve body 22 is held horizontally, along a virtual cylindrical processing surface (indicated by a two-dot chain line) equal to the inner diameter of the valve box sheet 5. The seat 24 is ground to form the valve seat surface 24a.

A pair of ring-shaped shaft seal members 25 and 26 are disposed between the valve body 22 and the bush 20, and the two shaft seal members 25 and 26 are opposed to each other in the axial direction of the valve stem 18. The tapered surfaces 25a and 26b are in contact with each other in a watertight manner.
An annular pressing plate 27 is disposed on the other end of the bush 20, and the pressing plate 27 is attached to the boss 19 with a tightening bolt 28. By tightening the tightening bolt 28, the shaft sealing materials 25 and 26 are pressed via the pressing plate 27 and the bush 20. As a result, both tapered surfaces 25
shaft sealing materials 25, 26 by wedge action of
Spreads inward and outward in the radial direction, and a surface pressure is generated on the boss portion 19 and the valve stem 18 to enhance the sealing performance.

The operation of the above configuration will be described below. The valve box O-ring 14 is provided between the inner surface of the valve box 12 and the valve box sheet 1.
By sealing the gap S with the outer peripheral surface of the valve 3, the entire amount of the fluid flowing into the valve box 12 passes through the internal flow path of the valve box sheet 13.

By driving the valve stem 18 to rotate in the forward or reverse direction, the valve body 22 is turned at an angle of 90 degrees around the axis of the valve stem within the valve seat 13 between the fully closed position and the fully opened position. Inverted, the outer peripheral surface of the valve body sheet 24 slides on the inner peripheral surface of the valve box sheet 13 in a watertight manner at the fully closed position, and closes the internal flow path of the valve box sheet 13.

In the fully closed state, the valve body 22 is in a posture perpendicular to the flow path axis of the valve box 12, and in a fully opened state in which the 90 ° reversing operation is performed, the valve body 22 is in a posture parallel to the flow path axis of the valve box 12, Since the valve body 22 is symmetrical with respect to the axis of the flow path, the flow of fluid in the valve case flow path is balanced on the left and right sides of the flow path.

The valve box sheet 13 is separate from the valve box 12,
Since there is a predetermined gap S between the two, even when the valve box 12 is deformed due to the water pressure or the fluctuation of the ground and the valve box 12 is deformed, the valve box sheet 13 is not deformed. Its shape is preserved. For this reason, the valve box sheet 13 contacts the valve body sheet 24 in a watertight manner while maintaining the consistency of the seat surface, so that no water leakage occurs and the valve body 22 is not restrained.

[0020]

As described above, according to the present invention, in the fully closed state in which the valve body sheet is disposed in parallel with the cross section of the valve body flow path, the plane including the center line of the valve body sheet surface is the valve body. By adopting a shape inclined at a predetermined angle with respect to the cross section of the flow path, the valve element is in a posture perpendicular to the axis of the flow path of the valve box in the fully closed state, and is fully opened in the 90-degree reversal operation. Becomes parallel to the axis of the flow path of the valve box, and the valve body is symmetrical with respect to the axis of the flow path, so that the fluid flow in the valve box flow path can be maintained in a balanced manner on the left and right sides of the flow path. it can.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a metal seat butterfly valve according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing the metal seat butterfly valve.

FIG. 3 is a schematic view showing a processing procedure of a valve body of the metal sheet butterfly valve.

FIG. 4 is a schematic view showing the metal seat butterfly valve.

FIG. 5 is a schematic view showing a conventional metal seat butterfly valve.

FIG. 6 is a schematic view illustrating the movement of a valve element in the metal seat butterfly valve.

FIG. 7 is a schematic diagram illustrating the movement of a valve element in the metal seat butterfly valve.

FIG. 8 is a schematic view showing a processing procedure of a valve body of the metal sheet butterfly valve.

[Explanation of symbols]

 S gap 11 metal seat butterfly valve 12 valve box 13 valve box seat 13a valve box seat surface 14 valve box O-ring 15 annular groove 16 stopper 17 bolt 18 valve stem 19 boss portion 20 bush 21 O-ring 22 valve body 23 pin 24 valve body Seat 24a Valve body seat surface 25, 26 Shaft sealing material 25a, 26b Tapered surface 27 Press plate 28 Tightening bolt

Claims (1)

[Claims] 1. A valve body is rotatably provided around an axis of a valve rod inside a valve box, a valve body sheet made of a metal material is provided on a peripheral portion of the valve body, and a valve box is provided on an outer peripheral surface of the valve body sheet. In a butterfly valve having a valve body seat surface that slides on a seat in a watertight manner, the valve body seat is a plane including a center line of the valve body sheet surface in a fully closed state in which the valve body is arranged in parallel with a cross section of a valve box flow path. Has a shape inclined at a predetermined angle with respect to the cross section of the valve case flow path.